328 BULLETIN 133, UNITED STATES NATIONAL MUSEUM 



grayer breast, more extensive white in crown stripe, with feathers 

 of occiput somewhat longer and fuller, and lack of whitish margins 

 on the lesser wing coverts. The young of alhiceps in juvenal plum- 

 age are duller brown than those of parvirostris. Specimens as- 

 signed to alhiceps include an adult male shot in willows near the 

 Rio Negro, south of General Roca, Rio Negro, December 3, 1920; 

 immature male and female from an altitude of 1,500 meters at 

 Potrerillos, Mendoza, March 17, 1921 ; and an immature female from 

 TOO meters' elevation at Tapia, Tucuman, April 7, 1921. The last 

 three are in juvenal plumage. The specimen from Tapia is consid- 

 erably paler above than those from Potrerillos, but is duller in color 

 than parvirostris, from the same locality, while in addition it has a 

 narrower bill and no white on the lesser wing coverts. As it was 

 taken in late fall it may be migrant from a higher elevation. 



Near General Roca, Rio Negro, Elaenia a. alhiceps was fairly 

 common among thickets of willows near the river, but was so shy 

 and retiring that it was difficult to secure. The call note of males, a 

 rapidly given loheur, was audil>le at some distance, but in the dense 

 growths of small willows the bird was difficult to see, while in more 

 open groves they were too wary to permit easy approach. Else- 

 where the species was recorded in the Andean foothills near Po- 

 trerillos, Mendoza, from March 17 to 21, where the birds were found 

 in growths of creosote bush {CovUlea cuneifolius) along streams. 

 These, as well as one found in dry brush near Tapia, Tucuman, on 

 April 7, were apparently in migration. 



ELAENIA PARVIROSTRIS Pelzeln 



Elainea parvirostris Pelzeln, Oni. Bras., pt. 2, 1868, p. 178. (Curytiba, 

 Parana, Brazil.) 



This form of Elaenia ranges from northern Buenos Aires (Lavalle, 

 Conchitas, etc.) northward through northern Argentina, Uruguay, 

 Paraguay, and Brazil. In general it extends eastward of the area 

 inhabited by alhiceps, and seems to frequent lower altitudes, since it 

 is not found in the Andes nor is it known in the colder area of Pata- 

 gonia on the south. Though similar in general appearance to alhi- 

 ceps, E. parvirostris is distinguished by broader bill, more greenish 

 dorsal coloration, lighter breast, shorter occipital feathers, and less 

 amount of white in crown. The lesser wing coverts in parvirostris 

 frequently are tipped with white, forming an indistinct third band 

 on the wing. The young in juvenal plumage are brighter, more 

 greenish in coloration than those of alhiceps. 



The five specimens secured include an adult male taken Novem- 

 ber 9, 1920, at the Estancia Los Yngleses, near Lavalle, Buenos Aires, 

 adult male and female from San Vicente, Uruguay, January 25 and 

 28, 1921, an immature female, in juvenal plumage, shot at Rio Negro, 



